A permanent magnet is that a magnet that is permanent, in contrast to an electromagnet, which only behaves like a magnet when an electric current is flowing through it.
Permanent magnets are made out of substances like magnetite (Fe3O4), 
the most magnetic naturally occurring mineral or neodymium, Samarium cobalt, a powerfully magnetic synthetic substance.
The Earth itself is a huge permanent magnet, though its magnetic field is quite weak relative to its size. Humans have used the magnetic field of the Earth for navigation since the compass was invented in ancient China.
Even the most powerful permanent magnet is not as strong as the strong electromagnets, so their applications are limited, but they still have very widely application, magnets can be found everywhere, including your hard disk, ATM and credit cards, speakers and microphones, electric motors, and toys.
Every permanent magnet generates a magnetic field, which circulates around the magnet is a distinct pattern. The size of the magnetic field is related to the size of the magnet and its strength. 
GME Magnets offers the highest quality Neodymium magnets with consistent performance and lowest price. 
Our Neodymium magnets are designed and manufactured to meet with quality standards using the latest technology. 

Magnetic Characteristics of N40SH